Dear all,

Additionally to what is mentioned below, deep percolation, if occurs, also
decreases effective irrigation.

Please note that DSSAT uses a "tipping bucket" approach for the computation
of the soil water balance which means it will consider as deep percolation
any amount of water in excess to fill the last layer of the soil.  In the
model's  documentation you can find a detailed explanation of the soil water
sub-model.

Regards,

Giovanni Munoz.



-----Original Message-----
From: DSSAT - Crop Models and Applications [mailto:[log in to unmask]] On
Behalf Of Richard Ogoshi
Sent: 13 July 2006 21:12
To: [log in to unmask]
Subject: Re: effective Irrigation


Hello Benjamin,
  Effective irrigation is the amount of irrigation water that infiltrates the
soil. Water may not infiltrate the soil due to runoff, evaporation, wind
blowing the water out of the plot (in the case of sprinkler irrigation), etc.
Irrigation efficiency is the ratio of amount of water that infiltrates the
soil to the total amount applied.
  Hope this helps.
Sincerely,
Richard

----- Original Message -----
From: Benjamin Fehling <[log in to unmask]>
Date: Thursday, July 13, 2006 5:27 am
Subject: effective Irrigation
To: [log in to unmask]

> Dear all,
>
> in my SoilWatBal.out file effective Irrigation for some of my test
> fields differs significantly from the applied amount. All irrigation
> inputs are correct. The efficient fraction factor in X-build is set to
> 1. What is exactly meant by effective irrigation and what factors
> effect the amount of the uneffective fraction?
>
> Thanks a lot for your advice.
>
> Benjamin Fehling
> Institute for vegetation ecology
> Tuebingen/Germany
>